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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
6 | * | |
c32b6b8e | 7 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 8 | * Added handling for CPU hotplug |
8ff69732 DJ |
9 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
10 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 11 | * |
1da177e4 LT |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License version 2 as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | */ | |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
1da177e4 LT |
20 | #include <linux/kernel.h> |
21 | #include <linux/module.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/notifier.h> | |
24 | #include <linux/cpufreq.h> | |
25 | #include <linux/delay.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/device.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/cpu.h> | |
31 | #include <linux/completion.h> | |
3fc54d37 | 32 | #include <linux/mutex.h> |
e00e56df | 33 | #include <linux/syscore_ops.h> |
1da177e4 | 34 | |
6f4f2723 TR |
35 | #include <trace/events/power.h> |
36 | ||
1da177e4 | 37 | /** |
cd878479 | 38 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
39 | * level driver of CPUFreq support, and its spinlock. This lock |
40 | * also protects the cpufreq_cpu_data array. | |
41 | */ | |
7d5e350f | 42 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 43 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
084f3493 TR |
44 | #ifdef CONFIG_HOTPLUG_CPU |
45 | /* This one keeps track of the previously set governor of a removed CPU */ | |
e77b89f1 | 46 | static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor); |
084f3493 | 47 | #endif |
1da177e4 LT |
48 | static DEFINE_SPINLOCK(cpufreq_driver_lock); |
49 | ||
5a01f2e8 VP |
50 | /* |
51 | * cpu_policy_rwsem is a per CPU reader-writer semaphore designed to cure | |
52 | * all cpufreq/hotplug/workqueue/etc related lock issues. | |
53 | * | |
54 | * The rules for this semaphore: | |
55 | * - Any routine that wants to read from the policy structure will | |
56 | * do a down_read on this semaphore. | |
57 | * - Any routine that will write to the policy structure and/or may take away | |
58 | * the policy altogether (eg. CPU hotplug), will hold this lock in write | |
59 | * mode before doing so. | |
60 | * | |
61 | * Additional rules: | |
62 | * - All holders of the lock should check to make sure that the CPU they | |
63 | * are concerned with are online after they get the lock. | |
64 | * - Governor routines that can be called in cpufreq hotplug path should not | |
65 | * take this sem as top level hotplug notifier handler takes this. | |
395913d0 MD |
66 | * - Lock should not be held across |
67 | * __cpufreq_governor(data, CPUFREQ_GOV_STOP); | |
5a01f2e8 | 68 | */ |
f1625066 | 69 | static DEFINE_PER_CPU(int, cpufreq_policy_cpu); |
5a01f2e8 VP |
70 | static DEFINE_PER_CPU(struct rw_semaphore, cpu_policy_rwsem); |
71 | ||
72 | #define lock_policy_rwsem(mode, cpu) \ | |
226528c6 | 73 | static int lock_policy_rwsem_##mode \ |
5a01f2e8 VP |
74 | (int cpu) \ |
75 | { \ | |
f1625066 | 76 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); \ |
5a01f2e8 VP |
77 | BUG_ON(policy_cpu == -1); \ |
78 | down_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
79 | if (unlikely(!cpu_online(cpu))) { \ | |
80 | up_##mode(&per_cpu(cpu_policy_rwsem, policy_cpu)); \ | |
81 | return -1; \ | |
82 | } \ | |
83 | \ | |
84 | return 0; \ | |
85 | } | |
86 | ||
87 | lock_policy_rwsem(read, cpu); | |
5a01f2e8 VP |
88 | |
89 | lock_policy_rwsem(write, cpu); | |
5a01f2e8 | 90 | |
226528c6 | 91 | static void unlock_policy_rwsem_read(int cpu) |
5a01f2e8 | 92 | { |
f1625066 | 93 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
94 | BUG_ON(policy_cpu == -1); |
95 | up_read(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
96 | } | |
5a01f2e8 | 97 | |
226528c6 | 98 | static void unlock_policy_rwsem_write(int cpu) |
5a01f2e8 | 99 | { |
f1625066 | 100 | int policy_cpu = per_cpu(cpufreq_policy_cpu, cpu); |
5a01f2e8 VP |
101 | BUG_ON(policy_cpu == -1); |
102 | up_write(&per_cpu(cpu_policy_rwsem, policy_cpu)); | |
103 | } | |
5a01f2e8 VP |
104 | |
105 | ||
1da177e4 | 106 | /* internal prototypes */ |
29464f28 DJ |
107 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
108 | unsigned int event); | |
5a01f2e8 | 109 | static unsigned int __cpufreq_get(unsigned int cpu); |
65f27f38 | 110 | static void handle_update(struct work_struct *work); |
1da177e4 LT |
111 | |
112 | /** | |
32ee8c3e DJ |
113 | * Two notifier lists: the "policy" list is involved in the |
114 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
115 | * "transition" list for kernel code that needs to handle |
116 | * changes to devices when the CPU clock speed changes. | |
117 | * The mutex locks both lists. | |
118 | */ | |
e041c683 | 119 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 120 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 121 | |
74212ca4 | 122 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
123 | static int __init init_cpufreq_transition_notifier_list(void) |
124 | { | |
125 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 126 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
127 | return 0; |
128 | } | |
b3438f82 | 129 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 130 | |
a7b422cd | 131 | static int off __read_mostly; |
da584455 | 132 | static int cpufreq_disabled(void) |
a7b422cd KRW |
133 | { |
134 | return off; | |
135 | } | |
136 | void disable_cpufreq(void) | |
137 | { | |
138 | off = 1; | |
139 | } | |
1da177e4 | 140 | static LIST_HEAD(cpufreq_governor_list); |
29464f28 | 141 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 142 | |
a9144436 | 143 | static struct cpufreq_policy *__cpufreq_cpu_get(unsigned int cpu, bool sysfs) |
1da177e4 LT |
144 | { |
145 | struct cpufreq_policy *data; | |
146 | unsigned long flags; | |
147 | ||
7a6aedfa | 148 | if (cpu >= nr_cpu_ids) |
1da177e4 LT |
149 | goto err_out; |
150 | ||
151 | /* get the cpufreq driver */ | |
152 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
153 | ||
154 | if (!cpufreq_driver) | |
155 | goto err_out_unlock; | |
156 | ||
157 | if (!try_module_get(cpufreq_driver->owner)) | |
158 | goto err_out_unlock; | |
159 | ||
160 | ||
161 | /* get the CPU */ | |
7a6aedfa | 162 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
163 | |
164 | if (!data) | |
165 | goto err_out_put_module; | |
166 | ||
a9144436 | 167 | if (!sysfs && !kobject_get(&data->kobj)) |
1da177e4 LT |
168 | goto err_out_put_module; |
169 | ||
1da177e4 | 170 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 LT |
171 | return data; |
172 | ||
7d5e350f | 173 | err_out_put_module: |
1da177e4 | 174 | module_put(cpufreq_driver->owner); |
7d5e350f | 175 | err_out_unlock: |
1da177e4 | 176 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
7d5e350f | 177 | err_out: |
1da177e4 LT |
178 | return NULL; |
179 | } | |
a9144436 SB |
180 | |
181 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) | |
182 | { | |
d5aaffa9 DB |
183 | if (cpufreq_disabled()) |
184 | return NULL; | |
185 | ||
a9144436 SB |
186 | return __cpufreq_cpu_get(cpu, false); |
187 | } | |
1da177e4 LT |
188 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
189 | ||
a9144436 SB |
190 | static struct cpufreq_policy *cpufreq_cpu_get_sysfs(unsigned int cpu) |
191 | { | |
192 | return __cpufreq_cpu_get(cpu, true); | |
193 | } | |
194 | ||
195 | static void __cpufreq_cpu_put(struct cpufreq_policy *data, bool sysfs) | |
196 | { | |
197 | if (!sysfs) | |
198 | kobject_put(&data->kobj); | |
199 | module_put(cpufreq_driver->owner); | |
200 | } | |
7d5e350f | 201 | |
1da177e4 LT |
202 | void cpufreq_cpu_put(struct cpufreq_policy *data) |
203 | { | |
d5aaffa9 DB |
204 | if (cpufreq_disabled()) |
205 | return; | |
206 | ||
a9144436 | 207 | __cpufreq_cpu_put(data, false); |
1da177e4 LT |
208 | } |
209 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
210 | ||
a9144436 SB |
211 | static void cpufreq_cpu_put_sysfs(struct cpufreq_policy *data) |
212 | { | |
213 | __cpufreq_cpu_put(data, true); | |
214 | } | |
1da177e4 | 215 | |
1da177e4 LT |
216 | /********************************************************************* |
217 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
218 | *********************************************************************/ | |
219 | ||
220 | /** | |
221 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
222 | * | |
223 | * This function alters the system "loops_per_jiffy" for the clock | |
224 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 225 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
226 | * per-CPU loops_per_jiffy value wherever possible. |
227 | */ | |
228 | #ifndef CONFIG_SMP | |
229 | static unsigned long l_p_j_ref; | |
230 | static unsigned int l_p_j_ref_freq; | |
231 | ||
858119e1 | 232 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 LT |
233 | { |
234 | if (ci->flags & CPUFREQ_CONST_LOOPS) | |
235 | return; | |
236 | ||
237 | if (!l_p_j_ref_freq) { | |
238 | l_p_j_ref = loops_per_jiffy; | |
239 | l_p_j_ref_freq = ci->old; | |
2d06d8c4 | 240 | pr_debug("saving %lu as reference value for loops_per_jiffy; " |
e08f5f5b | 241 | "freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq); |
1da177e4 | 242 | } |
d08de0c1 | 243 | if ((val == CPUFREQ_POSTCHANGE && ci->old != ci->new) || |
42d4dc3f | 244 | (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) { |
e08f5f5b GS |
245 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
246 | ci->new); | |
2d06d8c4 | 247 | pr_debug("scaling loops_per_jiffy to %lu " |
e08f5f5b | 248 | "for frequency %u kHz\n", loops_per_jiffy, ci->new); |
1da177e4 LT |
249 | } |
250 | } | |
251 | #else | |
e08f5f5b GS |
252 | static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
253 | { | |
254 | return; | |
255 | } | |
1da177e4 LT |
256 | #endif |
257 | ||
258 | ||
259 | /** | |
e4472cb3 DJ |
260 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies |
261 | * on frequency transition. | |
1da177e4 | 262 | * |
e4472cb3 DJ |
263 | * This function calls the transition notifiers and the "adjust_jiffies" |
264 | * function. It is called twice on all CPU frequency changes that have | |
32ee8c3e | 265 | * external effects. |
1da177e4 LT |
266 | */ |
267 | void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state) | |
268 | { | |
e4472cb3 DJ |
269 | struct cpufreq_policy *policy; |
270 | ||
1da177e4 LT |
271 | BUG_ON(irqs_disabled()); |
272 | ||
d5aaffa9 DB |
273 | if (cpufreq_disabled()) |
274 | return; | |
275 | ||
1da177e4 | 276 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 277 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e4472cb3 | 278 | state, freqs->new); |
1da177e4 | 279 | |
7a6aedfa | 280 | policy = per_cpu(cpufreq_cpu_data, freqs->cpu); |
1da177e4 | 281 | switch (state) { |
e4472cb3 | 282 | |
1da177e4 | 283 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 284 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
285 | * which is not equal to what the cpufreq core thinks is |
286 | * "old frequency". | |
1da177e4 LT |
287 | */ |
288 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
e4472cb3 DJ |
289 | if ((policy) && (policy->cpu == freqs->cpu) && |
290 | (policy->cur) && (policy->cur != freqs->old)) { | |
2d06d8c4 | 291 | pr_debug("Warning: CPU frequency is" |
e4472cb3 DJ |
292 | " %u, cpufreq assumed %u kHz.\n", |
293 | freqs->old, policy->cur); | |
294 | freqs->old = policy->cur; | |
1da177e4 LT |
295 | } |
296 | } | |
b4dfdbb3 | 297 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 298 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
299 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
300 | break; | |
e4472cb3 | 301 | |
1da177e4 LT |
302 | case CPUFREQ_POSTCHANGE: |
303 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
2d06d8c4 | 304 | pr_debug("FREQ: %lu - CPU: %lu", (unsigned long)freqs->new, |
6f4f2723 TR |
305 | (unsigned long)freqs->cpu); |
306 | trace_power_frequency(POWER_PSTATE, freqs->new, freqs->cpu); | |
25e41933 | 307 | trace_cpu_frequency(freqs->new, freqs->cpu); |
b4dfdbb3 | 308 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 309 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
310 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
311 | policy->cur = freqs->new; | |
1da177e4 LT |
312 | break; |
313 | } | |
1da177e4 LT |
314 | } |
315 | EXPORT_SYMBOL_GPL(cpufreq_notify_transition); | |
316 | ||
317 | ||
318 | ||
319 | /********************************************************************* | |
320 | * SYSFS INTERFACE * | |
321 | *********************************************************************/ | |
322 | ||
3bcb09a3 JF |
323 | static struct cpufreq_governor *__find_governor(const char *str_governor) |
324 | { | |
325 | struct cpufreq_governor *t; | |
326 | ||
327 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) | |
29464f28 | 328 | if (!strnicmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
329 | return t; |
330 | ||
331 | return NULL; | |
332 | } | |
333 | ||
1da177e4 LT |
334 | /** |
335 | * cpufreq_parse_governor - parse a governor string | |
336 | */ | |
905d77cd | 337 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
338 | struct cpufreq_governor **governor) |
339 | { | |
3bcb09a3 JF |
340 | int err = -EINVAL; |
341 | ||
1da177e4 | 342 | if (!cpufreq_driver) |
3bcb09a3 JF |
343 | goto out; |
344 | ||
1da177e4 LT |
345 | if (cpufreq_driver->setpolicy) { |
346 | if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { | |
347 | *policy = CPUFREQ_POLICY_PERFORMANCE; | |
3bcb09a3 | 348 | err = 0; |
e08f5f5b GS |
349 | } else if (!strnicmp(str_governor, "powersave", |
350 | CPUFREQ_NAME_LEN)) { | |
1da177e4 | 351 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 352 | err = 0; |
1da177e4 | 353 | } |
3bcb09a3 | 354 | } else if (cpufreq_driver->target) { |
1da177e4 | 355 | struct cpufreq_governor *t; |
3bcb09a3 | 356 | |
3fc54d37 | 357 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 JF |
358 | |
359 | t = __find_governor(str_governor); | |
360 | ||
ea714970 | 361 | if (t == NULL) { |
1a8e1463 | 362 | int ret; |
ea714970 | 363 | |
1a8e1463 KC |
364 | mutex_unlock(&cpufreq_governor_mutex); |
365 | ret = request_module("cpufreq_%s", str_governor); | |
366 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 367 | |
1a8e1463 KC |
368 | if (ret == 0) |
369 | t = __find_governor(str_governor); | |
ea714970 JF |
370 | } |
371 | ||
3bcb09a3 JF |
372 | if (t != NULL) { |
373 | *governor = t; | |
374 | err = 0; | |
1da177e4 | 375 | } |
3bcb09a3 | 376 | |
3fc54d37 | 377 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 378 | } |
29464f28 | 379 | out: |
3bcb09a3 | 380 | return err; |
1da177e4 | 381 | } |
1da177e4 LT |
382 | |
383 | ||
1da177e4 | 384 | /** |
e08f5f5b GS |
385 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
386 | * print out cpufreq information | |
1da177e4 LT |
387 | * |
388 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
389 | * "unsigned int". | |
390 | */ | |
391 | ||
32ee8c3e DJ |
392 | #define show_one(file_name, object) \ |
393 | static ssize_t show_##file_name \ | |
905d77cd | 394 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 395 | { \ |
29464f28 | 396 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
397 | } |
398 | ||
399 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
400 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 401 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
402 | show_one(scaling_min_freq, min); |
403 | show_one(scaling_max_freq, max); | |
404 | show_one(scaling_cur_freq, cur); | |
405 | ||
e08f5f5b GS |
406 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
407 | struct cpufreq_policy *policy); | |
7970e08b | 408 | |
1da177e4 LT |
409 | /** |
410 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
411 | */ | |
412 | #define store_one(file_name, object) \ | |
413 | static ssize_t store_##file_name \ | |
905d77cd | 414 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 415 | { \ |
f55c9c26 | 416 | unsigned int ret; \ |
1da177e4 LT |
417 | struct cpufreq_policy new_policy; \ |
418 | \ | |
419 | ret = cpufreq_get_policy(&new_policy, policy->cpu); \ | |
420 | if (ret) \ | |
421 | return -EINVAL; \ | |
422 | \ | |
29464f28 | 423 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
424 | if (ret != 1) \ |
425 | return -EINVAL; \ | |
426 | \ | |
7970e08b TR |
427 | ret = __cpufreq_set_policy(policy, &new_policy); \ |
428 | policy->user_policy.object = policy->object; \ | |
1da177e4 LT |
429 | \ |
430 | return ret ? ret : count; \ | |
431 | } | |
432 | ||
29464f28 DJ |
433 | store_one(scaling_min_freq, min); |
434 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
435 | |
436 | /** | |
437 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
438 | */ | |
905d77cd DJ |
439 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
440 | char *buf) | |
1da177e4 | 441 | { |
5a01f2e8 | 442 | unsigned int cur_freq = __cpufreq_get(policy->cpu); |
1da177e4 LT |
443 | if (!cur_freq) |
444 | return sprintf(buf, "<unknown>"); | |
445 | return sprintf(buf, "%u\n", cur_freq); | |
446 | } | |
447 | ||
448 | ||
449 | /** | |
450 | * show_scaling_governor - show the current policy for the specified CPU | |
451 | */ | |
905d77cd | 452 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 453 | { |
29464f28 | 454 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
455 | return sprintf(buf, "powersave\n"); |
456 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
457 | return sprintf(buf, "performance\n"); | |
458 | else if (policy->governor) | |
4b972f0b | 459 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 460 | policy->governor->name); |
1da177e4 LT |
461 | return -EINVAL; |
462 | } | |
463 | ||
464 | ||
465 | /** | |
466 | * store_scaling_governor - store policy for the specified CPU | |
467 | */ | |
905d77cd DJ |
468 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
469 | const char *buf, size_t count) | |
1da177e4 | 470 | { |
f55c9c26 | 471 | unsigned int ret; |
1da177e4 LT |
472 | char str_governor[16]; |
473 | struct cpufreq_policy new_policy; | |
474 | ||
475 | ret = cpufreq_get_policy(&new_policy, policy->cpu); | |
476 | if (ret) | |
477 | return ret; | |
478 | ||
29464f28 | 479 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
480 | if (ret != 1) |
481 | return -EINVAL; | |
482 | ||
e08f5f5b GS |
483 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
484 | &new_policy.governor)) | |
1da177e4 LT |
485 | return -EINVAL; |
486 | ||
7970e08b TR |
487 | /* Do not use cpufreq_set_policy here or the user_policy.max |
488 | will be wrongly overridden */ | |
7970e08b TR |
489 | ret = __cpufreq_set_policy(policy, &new_policy); |
490 | ||
491 | policy->user_policy.policy = policy->policy; | |
492 | policy->user_policy.governor = policy->governor; | |
7970e08b | 493 | |
e08f5f5b GS |
494 | if (ret) |
495 | return ret; | |
496 | else | |
497 | return count; | |
1da177e4 LT |
498 | } |
499 | ||
500 | /** | |
501 | * show_scaling_driver - show the cpufreq driver currently loaded | |
502 | */ | |
905d77cd | 503 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 504 | { |
4b972f0b | 505 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
506 | } |
507 | ||
508 | /** | |
509 | * show_scaling_available_governors - show the available CPUfreq governors | |
510 | */ | |
905d77cd DJ |
511 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
512 | char *buf) | |
1da177e4 LT |
513 | { |
514 | ssize_t i = 0; | |
515 | struct cpufreq_governor *t; | |
516 | ||
517 | if (!cpufreq_driver->target) { | |
518 | i += sprintf(buf, "performance powersave"); | |
519 | goto out; | |
520 | } | |
521 | ||
522 | list_for_each_entry(t, &cpufreq_governor_list, governor_list) { | |
29464f28 DJ |
523 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
524 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 525 | goto out; |
4b972f0b | 526 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 527 | } |
7d5e350f | 528 | out: |
1da177e4 LT |
529 | i += sprintf(&buf[i], "\n"); |
530 | return i; | |
531 | } | |
e8628dd0 | 532 | |
835481d9 | 533 | static ssize_t show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
534 | { |
535 | ssize_t i = 0; | |
536 | unsigned int cpu; | |
537 | ||
835481d9 | 538 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
539 | if (i) |
540 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
541 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
542 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 543 | break; |
1da177e4 LT |
544 | } |
545 | i += sprintf(&buf[i], "\n"); | |
546 | return i; | |
547 | } | |
548 | ||
e8628dd0 DW |
549 | /** |
550 | * show_related_cpus - show the CPUs affected by each transition even if | |
551 | * hw coordination is in use | |
552 | */ | |
553 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
554 | { | |
835481d9 | 555 | if (cpumask_empty(policy->related_cpus)) |
e8628dd0 DW |
556 | return show_cpus(policy->cpus, buf); |
557 | return show_cpus(policy->related_cpus, buf); | |
558 | } | |
559 | ||
560 | /** | |
561 | * show_affected_cpus - show the CPUs affected by each transition | |
562 | */ | |
563 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
564 | { | |
565 | return show_cpus(policy->cpus, buf); | |
566 | } | |
567 | ||
9e76988e | 568 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 569 | const char *buf, size_t count) |
9e76988e VP |
570 | { |
571 | unsigned int freq = 0; | |
572 | unsigned int ret; | |
573 | ||
879000f9 | 574 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
575 | return -EINVAL; |
576 | ||
577 | ret = sscanf(buf, "%u", &freq); | |
578 | if (ret != 1) | |
579 | return -EINVAL; | |
580 | ||
581 | policy->governor->store_setspeed(policy, freq); | |
582 | ||
583 | return count; | |
584 | } | |
585 | ||
586 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
587 | { | |
879000f9 | 588 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
589 | return sprintf(buf, "<unsupported>\n"); |
590 | ||
591 | return policy->governor->show_setspeed(policy, buf); | |
592 | } | |
1da177e4 | 593 | |
e2f74f35 | 594 | /** |
8bf1ac72 | 595 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
596 | */ |
597 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
598 | { | |
599 | unsigned int limit; | |
600 | int ret; | |
601 | if (cpufreq_driver->bios_limit) { | |
602 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
603 | if (!ret) | |
604 | return sprintf(buf, "%u\n", limit); | |
605 | } | |
606 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
607 | } | |
608 | ||
6dad2a29 BP |
609 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
610 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
611 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
612 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
613 | cpufreq_freq_attr_ro(scaling_available_governors); | |
614 | cpufreq_freq_attr_ro(scaling_driver); | |
615 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
616 | cpufreq_freq_attr_ro(bios_limit); | |
617 | cpufreq_freq_attr_ro(related_cpus); | |
618 | cpufreq_freq_attr_ro(affected_cpus); | |
619 | cpufreq_freq_attr_rw(scaling_min_freq); | |
620 | cpufreq_freq_attr_rw(scaling_max_freq); | |
621 | cpufreq_freq_attr_rw(scaling_governor); | |
622 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 623 | |
905d77cd | 624 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
625 | &cpuinfo_min_freq.attr, |
626 | &cpuinfo_max_freq.attr, | |
ed129784 | 627 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
628 | &scaling_min_freq.attr, |
629 | &scaling_max_freq.attr, | |
630 | &affected_cpus.attr, | |
e8628dd0 | 631 | &related_cpus.attr, |
1da177e4 LT |
632 | &scaling_governor.attr, |
633 | &scaling_driver.attr, | |
634 | &scaling_available_governors.attr, | |
9e76988e | 635 | &scaling_setspeed.attr, |
1da177e4 LT |
636 | NULL |
637 | }; | |
638 | ||
8aa84ad8 TR |
639 | struct kobject *cpufreq_global_kobject; |
640 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
641 | ||
29464f28 DJ |
642 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
643 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 644 | |
29464f28 | 645 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 646 | { |
905d77cd DJ |
647 | struct cpufreq_policy *policy = to_policy(kobj); |
648 | struct freq_attr *fattr = to_attr(attr); | |
0db4a8a9 | 649 | ssize_t ret = -EINVAL; |
a9144436 | 650 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 651 | if (!policy) |
0db4a8a9 | 652 | goto no_policy; |
5a01f2e8 VP |
653 | |
654 | if (lock_policy_rwsem_read(policy->cpu) < 0) | |
0db4a8a9 | 655 | goto fail; |
5a01f2e8 | 656 | |
e08f5f5b GS |
657 | if (fattr->show) |
658 | ret = fattr->show(policy, buf); | |
659 | else | |
660 | ret = -EIO; | |
661 | ||
5a01f2e8 | 662 | unlock_policy_rwsem_read(policy->cpu); |
0db4a8a9 | 663 | fail: |
a9144436 | 664 | cpufreq_cpu_put_sysfs(policy); |
0db4a8a9 | 665 | no_policy: |
1da177e4 LT |
666 | return ret; |
667 | } | |
668 | ||
905d77cd DJ |
669 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
670 | const char *buf, size_t count) | |
1da177e4 | 671 | { |
905d77cd DJ |
672 | struct cpufreq_policy *policy = to_policy(kobj); |
673 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 674 | ssize_t ret = -EINVAL; |
a9144436 | 675 | policy = cpufreq_cpu_get_sysfs(policy->cpu); |
1da177e4 | 676 | if (!policy) |
a07530b4 | 677 | goto no_policy; |
5a01f2e8 VP |
678 | |
679 | if (lock_policy_rwsem_write(policy->cpu) < 0) | |
a07530b4 | 680 | goto fail; |
5a01f2e8 | 681 | |
e08f5f5b GS |
682 | if (fattr->store) |
683 | ret = fattr->store(policy, buf, count); | |
684 | else | |
685 | ret = -EIO; | |
686 | ||
5a01f2e8 | 687 | unlock_policy_rwsem_write(policy->cpu); |
a07530b4 | 688 | fail: |
a9144436 | 689 | cpufreq_cpu_put_sysfs(policy); |
a07530b4 | 690 | no_policy: |
1da177e4 LT |
691 | return ret; |
692 | } | |
693 | ||
905d77cd | 694 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 695 | { |
905d77cd | 696 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 697 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
698 | complete(&policy->kobj_unregister); |
699 | } | |
700 | ||
52cf25d0 | 701 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
702 | .show = show, |
703 | .store = store, | |
704 | }; | |
705 | ||
706 | static struct kobj_type ktype_cpufreq = { | |
707 | .sysfs_ops = &sysfs_ops, | |
708 | .default_attrs = default_attrs, | |
709 | .release = cpufreq_sysfs_release, | |
710 | }; | |
711 | ||
4bfa042c TR |
712 | /* |
713 | * Returns: | |
714 | * Negative: Failure | |
715 | * 0: Success | |
716 | * Positive: When we have a managed CPU and the sysfs got symlinked | |
717 | */ | |
cf3289d0 AC |
718 | static int cpufreq_add_dev_policy(unsigned int cpu, |
719 | struct cpufreq_policy *policy, | |
8a25a2fd | 720 | struct device *dev) |
ecf7e461 DJ |
721 | { |
722 | int ret = 0; | |
723 | #ifdef CONFIG_SMP | |
724 | unsigned long flags; | |
725 | unsigned int j; | |
ecf7e461 | 726 | #ifdef CONFIG_HOTPLUG_CPU |
e77b89f1 DM |
727 | struct cpufreq_governor *gov; |
728 | ||
729 | gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu)); | |
730 | if (gov) { | |
731 | policy->governor = gov; | |
2d06d8c4 | 732 | pr_debug("Restoring governor %s for cpu %d\n", |
ecf7e461 DJ |
733 | policy->governor->name, cpu); |
734 | } | |
735 | #endif | |
736 | ||
737 | for_each_cpu(j, policy->cpus) { | |
738 | struct cpufreq_policy *managed_policy; | |
739 | ||
740 | if (cpu == j) | |
741 | continue; | |
742 | ||
743 | /* Check for existing affected CPUs. | |
744 | * They may not be aware of it due to CPU Hotplug. | |
745 | * cpufreq_cpu_put is called when the device is removed | |
746 | * in __cpufreq_remove_dev() | |
747 | */ | |
748 | managed_policy = cpufreq_cpu_get(j); | |
749 | if (unlikely(managed_policy)) { | |
750 | ||
751 | /* Set proper policy_cpu */ | |
752 | unlock_policy_rwsem_write(cpu); | |
f1625066 | 753 | per_cpu(cpufreq_policy_cpu, cpu) = managed_policy->cpu; |
ecf7e461 DJ |
754 | |
755 | if (lock_policy_rwsem_write(cpu) < 0) { | |
756 | /* Should not go through policy unlock path */ | |
757 | if (cpufreq_driver->exit) | |
758 | cpufreq_driver->exit(policy); | |
759 | cpufreq_cpu_put(managed_policy); | |
760 | return -EBUSY; | |
761 | } | |
762 | ||
f6a7409c VK |
763 | __cpufreq_governor(managed_policy, CPUFREQ_GOV_STOP); |
764 | ||
ecf7e461 DJ |
765 | spin_lock_irqsave(&cpufreq_driver_lock, flags); |
766 | cpumask_copy(managed_policy->cpus, policy->cpus); | |
767 | per_cpu(cpufreq_cpu_data, cpu) = managed_policy; | |
768 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
769 | ||
f6a7409c VK |
770 | __cpufreq_governor(managed_policy, CPUFREQ_GOV_START); |
771 | __cpufreq_governor(managed_policy, CPUFREQ_GOV_LIMITS); | |
772 | ||
2d06d8c4 | 773 | pr_debug("CPU already managed, adding link\n"); |
8a25a2fd | 774 | ret = sysfs_create_link(&dev->kobj, |
ecf7e461 DJ |
775 | &managed_policy->kobj, |
776 | "cpufreq"); | |
777 | if (ret) | |
778 | cpufreq_cpu_put(managed_policy); | |
779 | /* | |
780 | * Success. We only needed to be added to the mask. | |
781 | * Call driver->exit() because only the cpu parent of | |
782 | * the kobj needed to call init(). | |
783 | */ | |
784 | if (cpufreq_driver->exit) | |
785 | cpufreq_driver->exit(policy); | |
4bfa042c TR |
786 | |
787 | if (!ret) | |
788 | return 1; | |
789 | else | |
790 | return ret; | |
ecf7e461 DJ |
791 | } |
792 | } | |
793 | #endif | |
794 | return ret; | |
795 | } | |
796 | ||
797 | ||
19d6f7ec | 798 | /* symlink affected CPUs */ |
cf3289d0 AC |
799 | static int cpufreq_add_dev_symlink(unsigned int cpu, |
800 | struct cpufreq_policy *policy) | |
19d6f7ec DJ |
801 | { |
802 | unsigned int j; | |
803 | int ret = 0; | |
804 | ||
805 | for_each_cpu(j, policy->cpus) { | |
806 | struct cpufreq_policy *managed_policy; | |
8a25a2fd | 807 | struct device *cpu_dev; |
19d6f7ec DJ |
808 | |
809 | if (j == cpu) | |
810 | continue; | |
811 | if (!cpu_online(j)) | |
812 | continue; | |
813 | ||
2d06d8c4 | 814 | pr_debug("CPU %u already managed, adding link\n", j); |
19d6f7ec | 815 | managed_policy = cpufreq_cpu_get(cpu); |
8a25a2fd KS |
816 | cpu_dev = get_cpu_device(j); |
817 | ret = sysfs_create_link(&cpu_dev->kobj, &policy->kobj, | |
19d6f7ec DJ |
818 | "cpufreq"); |
819 | if (ret) { | |
820 | cpufreq_cpu_put(managed_policy); | |
821 | return ret; | |
822 | } | |
823 | } | |
824 | return ret; | |
825 | } | |
826 | ||
cf3289d0 AC |
827 | static int cpufreq_add_dev_interface(unsigned int cpu, |
828 | struct cpufreq_policy *policy, | |
8a25a2fd | 829 | struct device *dev) |
909a694e | 830 | { |
ecf7e461 | 831 | struct cpufreq_policy new_policy; |
909a694e DJ |
832 | struct freq_attr **drv_attr; |
833 | unsigned long flags; | |
834 | int ret = 0; | |
835 | unsigned int j; | |
836 | ||
837 | /* prepare interface data */ | |
838 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, | |
8a25a2fd | 839 | &dev->kobj, "cpufreq"); |
909a694e DJ |
840 | if (ret) |
841 | return ret; | |
842 | ||
843 | /* set up files for this cpu device */ | |
844 | drv_attr = cpufreq_driver->attr; | |
845 | while ((drv_attr) && (*drv_attr)) { | |
846 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); | |
847 | if (ret) | |
848 | goto err_out_kobj_put; | |
849 | drv_attr++; | |
850 | } | |
851 | if (cpufreq_driver->get) { | |
852 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); | |
853 | if (ret) | |
854 | goto err_out_kobj_put; | |
855 | } | |
856 | if (cpufreq_driver->target) { | |
857 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
858 | if (ret) | |
859 | goto err_out_kobj_put; | |
860 | } | |
e2f74f35 TR |
861 | if (cpufreq_driver->bios_limit) { |
862 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); | |
863 | if (ret) | |
864 | goto err_out_kobj_put; | |
865 | } | |
909a694e DJ |
866 | |
867 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
868 | for_each_cpu(j, policy->cpus) { | |
bec037aa JL |
869 | if (!cpu_online(j)) |
870 | continue; | |
909a694e | 871 | per_cpu(cpufreq_cpu_data, j) = policy; |
f1625066 | 872 | per_cpu(cpufreq_policy_cpu, j) = policy->cpu; |
909a694e DJ |
873 | } |
874 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
875 | ||
876 | ret = cpufreq_add_dev_symlink(cpu, policy); | |
ecf7e461 DJ |
877 | if (ret) |
878 | goto err_out_kobj_put; | |
879 | ||
880 | memcpy(&new_policy, policy, sizeof(struct cpufreq_policy)); | |
881 | /* assure that the starting sequence is run in __cpufreq_set_policy */ | |
882 | policy->governor = NULL; | |
883 | ||
884 | /* set default policy */ | |
885 | ret = __cpufreq_set_policy(policy, &new_policy); | |
886 | policy->user_policy.policy = policy->policy; | |
887 | policy->user_policy.governor = policy->governor; | |
888 | ||
889 | if (ret) { | |
2d06d8c4 | 890 | pr_debug("setting policy failed\n"); |
ecf7e461 DJ |
891 | if (cpufreq_driver->exit) |
892 | cpufreq_driver->exit(policy); | |
893 | } | |
909a694e DJ |
894 | return ret; |
895 | ||
896 | err_out_kobj_put: | |
897 | kobject_put(&policy->kobj); | |
898 | wait_for_completion(&policy->kobj_unregister); | |
899 | return ret; | |
900 | } | |
901 | ||
1da177e4 LT |
902 | |
903 | /** | |
904 | * cpufreq_add_dev - add a CPU device | |
905 | * | |
32ee8c3e | 906 | * Adds the cpufreq interface for a CPU device. |
3f4a782b MD |
907 | * |
908 | * The Oracle says: try running cpufreq registration/unregistration concurrently | |
909 | * with with cpu hotplugging and all hell will break loose. Tried to clean this | |
910 | * mess up, but more thorough testing is needed. - Mathieu | |
1da177e4 | 911 | */ |
8a25a2fd | 912 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 913 | { |
8a25a2fd | 914 | unsigned int cpu = dev->id; |
90e41bac | 915 | int ret = 0, found = 0; |
1da177e4 | 916 | struct cpufreq_policy *policy; |
1da177e4 LT |
917 | unsigned long flags; |
918 | unsigned int j; | |
90e41bac PB |
919 | #ifdef CONFIG_HOTPLUG_CPU |
920 | int sibling; | |
921 | #endif | |
1da177e4 | 922 | |
c32b6b8e AR |
923 | if (cpu_is_offline(cpu)) |
924 | return 0; | |
925 | ||
2d06d8c4 | 926 | pr_debug("adding CPU %u\n", cpu); |
1da177e4 LT |
927 | |
928 | #ifdef CONFIG_SMP | |
929 | /* check whether a different CPU already registered this | |
930 | * CPU because it is in the same boat. */ | |
931 | policy = cpufreq_cpu_get(cpu); | |
932 | if (unlikely(policy)) { | |
8ff69732 | 933 | cpufreq_cpu_put(policy); |
1da177e4 LT |
934 | return 0; |
935 | } | |
936 | #endif | |
937 | ||
938 | if (!try_module_get(cpufreq_driver->owner)) { | |
939 | ret = -EINVAL; | |
940 | goto module_out; | |
941 | } | |
942 | ||
059019a3 | 943 | ret = -ENOMEM; |
e98df50c | 944 | policy = kzalloc(sizeof(struct cpufreq_policy), GFP_KERNEL); |
059019a3 | 945 | if (!policy) |
1da177e4 | 946 | goto nomem_out; |
059019a3 DJ |
947 | |
948 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
3f4a782b | 949 | goto err_free_policy; |
059019a3 DJ |
950 | |
951 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
3f4a782b | 952 | goto err_free_cpumask; |
1da177e4 LT |
953 | |
954 | policy->cpu = cpu; | |
835481d9 | 955 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 956 | |
5a01f2e8 | 957 | /* Initially set CPU itself as the policy_cpu */ |
f1625066 | 958 | per_cpu(cpufreq_policy_cpu, cpu) = cpu; |
3f4a782b MD |
959 | ret = (lock_policy_rwsem_write(cpu) < 0); |
960 | WARN_ON(ret); | |
5a01f2e8 | 961 | |
1da177e4 | 962 | init_completion(&policy->kobj_unregister); |
65f27f38 | 963 | INIT_WORK(&policy->update, handle_update); |
1da177e4 | 964 | |
8122c6ce | 965 | /* Set governor before ->init, so that driver could check it */ |
90e41bac PB |
966 | #ifdef CONFIG_HOTPLUG_CPU |
967 | for_each_online_cpu(sibling) { | |
968 | struct cpufreq_policy *cp = per_cpu(cpufreq_cpu_data, sibling); | |
969 | if (cp && cp->governor && | |
970 | (cpumask_test_cpu(cpu, cp->related_cpus))) { | |
971 | policy->governor = cp->governor; | |
972 | found = 1; | |
973 | break; | |
974 | } | |
975 | } | |
976 | #endif | |
977 | if (!found) | |
978 | policy->governor = CPUFREQ_DEFAULT_GOVERNOR; | |
1da177e4 LT |
979 | /* call driver. From then on the cpufreq must be able |
980 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
981 | */ | |
982 | ret = cpufreq_driver->init(policy); | |
983 | if (ret) { | |
2d06d8c4 | 984 | pr_debug("initialization failed\n"); |
3f4a782b | 985 | goto err_unlock_policy; |
1da177e4 | 986 | } |
643ae6e8 VK |
987 | |
988 | /* | |
989 | * affected cpus must always be the one, which are online. We aren't | |
990 | * managing offline cpus here. | |
991 | */ | |
992 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
993 | ||
187d9f4e MC |
994 | policy->user_policy.min = policy->min; |
995 | policy->user_policy.max = policy->max; | |
1da177e4 | 996 | |
a1531acd TR |
997 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
998 | CPUFREQ_START, policy); | |
999 | ||
8a25a2fd | 1000 | ret = cpufreq_add_dev_policy(cpu, policy, dev); |
4bfa042c TR |
1001 | if (ret) { |
1002 | if (ret > 0) | |
1003 | /* This is a managed cpu, symlink created, | |
1004 | exit with 0 */ | |
1005 | ret = 0; | |
ecf7e461 | 1006 | goto err_unlock_policy; |
4bfa042c | 1007 | } |
1da177e4 | 1008 | |
8a25a2fd | 1009 | ret = cpufreq_add_dev_interface(cpu, policy, dev); |
19d6f7ec DJ |
1010 | if (ret) |
1011 | goto err_out_unregister; | |
8ff69732 | 1012 | |
dca02613 LW |
1013 | unlock_policy_rwsem_write(cpu); |
1014 | ||
038c5b3e | 1015 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
1da177e4 | 1016 | module_put(cpufreq_driver->owner); |
2d06d8c4 | 1017 | pr_debug("initialization complete\n"); |
87c32271 | 1018 | |
1da177e4 LT |
1019 | return 0; |
1020 | ||
1021 | ||
1022 | err_out_unregister: | |
1023 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
835481d9 | 1024 | for_each_cpu(j, policy->cpus) |
7a6aedfa | 1025 | per_cpu(cpufreq_cpu_data, j) = NULL; |
1da177e4 LT |
1026 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1027 | ||
c10997f6 | 1028 | kobject_put(&policy->kobj); |
1da177e4 LT |
1029 | wait_for_completion(&policy->kobj_unregister); |
1030 | ||
3f4a782b | 1031 | err_unlock_policy: |
45709118 | 1032 | unlock_policy_rwsem_write(cpu); |
cad70a6a | 1033 | free_cpumask_var(policy->related_cpus); |
3f4a782b MD |
1034 | err_free_cpumask: |
1035 | free_cpumask_var(policy->cpus); | |
1036 | err_free_policy: | |
1da177e4 | 1037 | kfree(policy); |
1da177e4 LT |
1038 | nomem_out: |
1039 | module_put(cpufreq_driver->owner); | |
c32b6b8e | 1040 | module_out: |
1da177e4 LT |
1041 | return ret; |
1042 | } | |
1043 | ||
b8eed8af VK |
1044 | static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
1045 | { | |
1046 | int j; | |
1047 | ||
1048 | policy->last_cpu = policy->cpu; | |
1049 | policy->cpu = cpu; | |
1050 | ||
1051 | for_each_cpu(j, policy->cpus) { | |
1052 | if (!cpu_online(j)) | |
1053 | continue; | |
1054 | per_cpu(cpufreq_policy_cpu, j) = cpu; | |
1055 | } | |
1056 | ||
1057 | #ifdef CONFIG_CPU_FREQ_TABLE | |
1058 | cpufreq_frequency_table_update_policy_cpu(policy); | |
1059 | #endif | |
1060 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, | |
1061 | CPUFREQ_UPDATE_POLICY_CPU, policy); | |
1062 | } | |
1da177e4 LT |
1063 | |
1064 | /** | |
5a01f2e8 | 1065 | * __cpufreq_remove_dev - remove a CPU device |
1da177e4 LT |
1066 | * |
1067 | * Removes the cpufreq interface for a CPU device. | |
5a01f2e8 VP |
1068 | * Caller should already have policy_rwsem in write mode for this CPU. |
1069 | * This routine frees the rwsem before returning. | |
1da177e4 | 1070 | */ |
8a25a2fd | 1071 | static int __cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
1da177e4 | 1072 | { |
b8eed8af | 1073 | unsigned int cpu = dev->id, ret, cpus; |
1da177e4 LT |
1074 | unsigned long flags; |
1075 | struct cpufreq_policy *data; | |
499bca9b AW |
1076 | struct kobject *kobj; |
1077 | struct completion *cmp; | |
8a25a2fd | 1078 | struct device *cpu_dev; |
1da177e4 | 1079 | |
b8eed8af | 1080 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 LT |
1081 | |
1082 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
7a6aedfa | 1083 | data = per_cpu(cpufreq_cpu_data, cpu); |
1da177e4 LT |
1084 | |
1085 | if (!data) { | |
b8eed8af | 1086 | pr_debug("%s: No cpu_data found\n", __func__); |
1da177e4 | 1087 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5a01f2e8 | 1088 | unlock_policy_rwsem_write(cpu); |
1da177e4 LT |
1089 | return -EINVAL; |
1090 | } | |
1da177e4 | 1091 | |
b8eed8af | 1092 | if (cpufreq_driver->target) |
f6a7409c | 1093 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
084f3493 TR |
1094 | |
1095 | #ifdef CONFIG_HOTPLUG_CPU | |
e77b89f1 DM |
1096 | strncpy(per_cpu(cpufreq_cpu_governor, cpu), data->governor->name, |
1097 | CPUFREQ_NAME_LEN); | |
084f3493 TR |
1098 | #endif |
1099 | ||
b8eed8af VK |
1100 | per_cpu(cpufreq_cpu_data, cpu) = NULL; |
1101 | cpus = cpumask_weight(data->cpus); | |
1102 | cpumask_clear_cpu(cpu, data->cpus); | |
1da177e4 | 1103 | |
b8eed8af VK |
1104 | if (unlikely((cpu == data->cpu) && (cpus > 1))) { |
1105 | /* first sibling now owns the new sysfs dir */ | |
1106 | cpu_dev = get_cpu_device(cpumask_first(data->cpus)); | |
1107 | sysfs_remove_link(&cpu_dev->kobj, "cpufreq"); | |
1108 | ret = kobject_move(&data->kobj, &cpu_dev->kobj); | |
1109 | if (ret) { | |
1110 | pr_err("%s: Failed to move kobj: %d", __func__, ret); | |
1111 | cpumask_set_cpu(cpu, data->cpus); | |
1112 | ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj, | |
1113 | "cpufreq"); | |
1114 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
499bca9b | 1115 | unlock_policy_rwsem_write(cpu); |
b8eed8af | 1116 | return -EINVAL; |
1da177e4 | 1117 | } |
b8eed8af VK |
1118 | |
1119 | update_policy_cpu(data, cpu_dev->id); | |
1120 | pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n", | |
1121 | __func__, cpu_dev->id, cpu); | |
1da177e4 | 1122 | } |
1da177e4 | 1123 | |
b8eed8af | 1124 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); |
5a01f2e8 | 1125 | |
b8eed8af VK |
1126 | pr_debug("%s: removing link, cpu: %d\n", __func__, cpu); |
1127 | cpufreq_cpu_put(data); | |
499bca9b | 1128 | unlock_policy_rwsem_write(cpu); |
b8eed8af | 1129 | sysfs_remove_link(&dev->kobj, "cpufreq"); |
1da177e4 | 1130 | |
b8eed8af VK |
1131 | /* If cpu is last user of policy, free policy */ |
1132 | if (cpus == 1) { | |
1133 | lock_policy_rwsem_write(cpu); | |
1134 | kobj = &data->kobj; | |
1135 | cmp = &data->kobj_unregister; | |
1136 | unlock_policy_rwsem_write(cpu); | |
1137 | kobject_put(kobj); | |
7d26e2d5 | 1138 | |
b8eed8af VK |
1139 | /* we need to make sure that the underlying kobj is actually |
1140 | * not referenced anymore by anybody before we proceed with | |
1141 | * unloading. | |
1142 | */ | |
1143 | pr_debug("waiting for dropping of refcount\n"); | |
1144 | wait_for_completion(cmp); | |
1145 | pr_debug("wait complete\n"); | |
27ecddc2 | 1146 | |
27ecddc2 | 1147 | lock_policy_rwsem_write(cpu); |
b8eed8af VK |
1148 | if (cpufreq_driver->exit) |
1149 | cpufreq_driver->exit(data); | |
1150 | unlock_policy_rwsem_write(cpu); | |
27ecddc2 | 1151 | |
b8eed8af VK |
1152 | free_cpumask_var(data->related_cpus); |
1153 | free_cpumask_var(data->cpus); | |
1154 | kfree(data); | |
1155 | } else if (cpufreq_driver->target) { | |
1156 | __cpufreq_governor(data, CPUFREQ_GOV_START); | |
1157 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); | |
1158 | } | |
1da177e4 | 1159 | |
1da177e4 LT |
1160 | return 0; |
1161 | } | |
1162 | ||
1163 | ||
8a25a2fd | 1164 | static int cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1165 | { |
8a25a2fd | 1166 | unsigned int cpu = dev->id; |
5a01f2e8 | 1167 | int retval; |
ec28297a VP |
1168 | |
1169 | if (cpu_is_offline(cpu)) | |
1170 | return 0; | |
1171 | ||
5a01f2e8 VP |
1172 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1173 | BUG(); | |
1174 | ||
8a25a2fd | 1175 | retval = __cpufreq_remove_dev(dev, sif); |
5a01f2e8 VP |
1176 | return retval; |
1177 | } | |
1178 | ||
1179 | ||
65f27f38 | 1180 | static void handle_update(struct work_struct *work) |
1da177e4 | 1181 | { |
65f27f38 DH |
1182 | struct cpufreq_policy *policy = |
1183 | container_of(work, struct cpufreq_policy, update); | |
1184 | unsigned int cpu = policy->cpu; | |
2d06d8c4 | 1185 | pr_debug("handle_update for cpu %u called\n", cpu); |
1da177e4 LT |
1186 | cpufreq_update_policy(cpu); |
1187 | } | |
1188 | ||
1189 | /** | |
1190 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble. | |
1191 | * @cpu: cpu number | |
1192 | * @old_freq: CPU frequency the kernel thinks the CPU runs at | |
1193 | * @new_freq: CPU frequency the CPU actually runs at | |
1194 | * | |
29464f28 DJ |
1195 | * We adjust to current frequency first, and need to clean up later. |
1196 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1197 | */ |
e08f5f5b GS |
1198 | static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, |
1199 | unsigned int new_freq) | |
1da177e4 LT |
1200 | { |
1201 | struct cpufreq_freqs freqs; | |
1202 | ||
2d06d8c4 | 1203 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing " |
1da177e4 LT |
1204 | "core thinks of %u, is %u kHz.\n", old_freq, new_freq); |
1205 | ||
1206 | freqs.cpu = cpu; | |
1207 | freqs.old = old_freq; | |
1208 | freqs.new = new_freq; | |
1209 | cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); | |
1210 | cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); | |
1211 | } | |
1212 | ||
1213 | ||
32ee8c3e | 1214 | /** |
4ab70df4 | 1215 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1216 | * @cpu: CPU number |
1217 | * | |
1218 | * This is the last known freq, without actually getting it from the driver. | |
1219 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1220 | */ | |
1221 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1222 | { | |
1223 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
e08f5f5b | 1224 | unsigned int ret_freq = 0; |
95235ca2 VP |
1225 | |
1226 | if (policy) { | |
e08f5f5b | 1227 | ret_freq = policy->cur; |
95235ca2 VP |
1228 | cpufreq_cpu_put(policy); |
1229 | } | |
1230 | ||
4d34a67d | 1231 | return ret_freq; |
95235ca2 VP |
1232 | } |
1233 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1234 | ||
3d737108 JB |
1235 | /** |
1236 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1237 | * @cpu: CPU number | |
1238 | * | |
1239 | * Just return the max possible frequency for a given CPU. | |
1240 | */ | |
1241 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1242 | { | |
1243 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1244 | unsigned int ret_freq = 0; | |
1245 | ||
1246 | if (policy) { | |
1247 | ret_freq = policy->max; | |
1248 | cpufreq_cpu_put(policy); | |
1249 | } | |
1250 | ||
1251 | return ret_freq; | |
1252 | } | |
1253 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1254 | ||
95235ca2 | 1255 | |
5a01f2e8 | 1256 | static unsigned int __cpufreq_get(unsigned int cpu) |
1da177e4 | 1257 | { |
7a6aedfa | 1258 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
e08f5f5b | 1259 | unsigned int ret_freq = 0; |
1da177e4 | 1260 | |
1da177e4 | 1261 | if (!cpufreq_driver->get) |
4d34a67d | 1262 | return ret_freq; |
1da177e4 | 1263 | |
e08f5f5b | 1264 | ret_freq = cpufreq_driver->get(cpu); |
1da177e4 | 1265 | |
e08f5f5b GS |
1266 | if (ret_freq && policy->cur && |
1267 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { | |
1268 | /* verify no discrepancy between actual and | |
1269 | saved value exists */ | |
1270 | if (unlikely(ret_freq != policy->cur)) { | |
1271 | cpufreq_out_of_sync(cpu, policy->cur, ret_freq); | |
1da177e4 LT |
1272 | schedule_work(&policy->update); |
1273 | } | |
1274 | } | |
1275 | ||
4d34a67d | 1276 | return ret_freq; |
5a01f2e8 | 1277 | } |
1da177e4 | 1278 | |
5a01f2e8 VP |
1279 | /** |
1280 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1281 | * @cpu: CPU number | |
1282 | * | |
1283 | * Get the CPU current (static) CPU frequency | |
1284 | */ | |
1285 | unsigned int cpufreq_get(unsigned int cpu) | |
1286 | { | |
1287 | unsigned int ret_freq = 0; | |
1288 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1289 | ||
1290 | if (!policy) | |
1291 | goto out; | |
1292 | ||
1293 | if (unlikely(lock_policy_rwsem_read(cpu))) | |
1294 | goto out_policy; | |
1295 | ||
1296 | ret_freq = __cpufreq_get(cpu); | |
1297 | ||
1298 | unlock_policy_rwsem_read(cpu); | |
1da177e4 | 1299 | |
5a01f2e8 VP |
1300 | out_policy: |
1301 | cpufreq_cpu_put(policy); | |
1302 | out: | |
4d34a67d | 1303 | return ret_freq; |
1da177e4 LT |
1304 | } |
1305 | EXPORT_SYMBOL(cpufreq_get); | |
1306 | ||
8a25a2fd KS |
1307 | static struct subsys_interface cpufreq_interface = { |
1308 | .name = "cpufreq", | |
1309 | .subsys = &cpu_subsys, | |
1310 | .add_dev = cpufreq_add_dev, | |
1311 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1312 | }; |
1313 | ||
1da177e4 | 1314 | |
42d4dc3f | 1315 | /** |
e00e56df RW |
1316 | * cpufreq_bp_suspend - Prepare the boot CPU for system suspend. |
1317 | * | |
1318 | * This function is only executed for the boot processor. The other CPUs | |
1319 | * have been put offline by means of CPU hotplug. | |
42d4dc3f | 1320 | */ |
e00e56df | 1321 | static int cpufreq_bp_suspend(void) |
42d4dc3f | 1322 | { |
e08f5f5b | 1323 | int ret = 0; |
4bc5d341 | 1324 | |
e00e56df | 1325 | int cpu = smp_processor_id(); |
42d4dc3f BH |
1326 | struct cpufreq_policy *cpu_policy; |
1327 | ||
2d06d8c4 | 1328 | pr_debug("suspending cpu %u\n", cpu); |
42d4dc3f | 1329 | |
e00e56df | 1330 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
42d4dc3f BH |
1331 | cpu_policy = cpufreq_cpu_get(cpu); |
1332 | if (!cpu_policy) | |
e00e56df | 1333 | return 0; |
42d4dc3f BH |
1334 | |
1335 | if (cpufreq_driver->suspend) { | |
7ca64e2d | 1336 | ret = cpufreq_driver->suspend(cpu_policy); |
ce6c3997 | 1337 | if (ret) |
42d4dc3f BH |
1338 | printk(KERN_ERR "cpufreq: suspend failed in ->suspend " |
1339 | "step on CPU %u\n", cpu_policy->cpu); | |
42d4dc3f BH |
1340 | } |
1341 | ||
42d4dc3f | 1342 | cpufreq_cpu_put(cpu_policy); |
c9060494 | 1343 | return ret; |
42d4dc3f BH |
1344 | } |
1345 | ||
1da177e4 | 1346 | /** |
e00e56df | 1347 | * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU. |
1da177e4 LT |
1348 | * |
1349 | * 1.) resume CPUfreq hardware support (cpufreq_driver->resume()) | |
ce6c3997 DB |
1350 | * 2.) schedule call cpufreq_update_policy() ASAP as interrupts are |
1351 | * restored. It will verify that the current freq is in sync with | |
1352 | * what we believe it to be. This is a bit later than when it | |
1353 | * should be, but nonethteless it's better than calling | |
1354 | * cpufreq_driver->get() here which might re-enable interrupts... | |
e00e56df RW |
1355 | * |
1356 | * This function is only executed for the boot CPU. The other CPUs have not | |
1357 | * been turned on yet. | |
1da177e4 | 1358 | */ |
e00e56df | 1359 | static void cpufreq_bp_resume(void) |
1da177e4 | 1360 | { |
e08f5f5b | 1361 | int ret = 0; |
4bc5d341 | 1362 | |
e00e56df | 1363 | int cpu = smp_processor_id(); |
1da177e4 LT |
1364 | struct cpufreq_policy *cpu_policy; |
1365 | ||
2d06d8c4 | 1366 | pr_debug("resuming cpu %u\n", cpu); |
1da177e4 | 1367 | |
e00e56df | 1368 | /* If there's no policy for the boot CPU, we have nothing to do. */ |
1da177e4 LT |
1369 | cpu_policy = cpufreq_cpu_get(cpu); |
1370 | if (!cpu_policy) | |
e00e56df | 1371 | return; |
1da177e4 LT |
1372 | |
1373 | if (cpufreq_driver->resume) { | |
1374 | ret = cpufreq_driver->resume(cpu_policy); | |
1375 | if (ret) { | |
1376 | printk(KERN_ERR "cpufreq: resume failed in ->resume " | |
1377 | "step on CPU %u\n", cpu_policy->cpu); | |
c9060494 | 1378 | goto fail; |
1da177e4 LT |
1379 | } |
1380 | } | |
1381 | ||
1da177e4 | 1382 | schedule_work(&cpu_policy->update); |
ce6c3997 | 1383 | |
c9060494 | 1384 | fail: |
1da177e4 | 1385 | cpufreq_cpu_put(cpu_policy); |
1da177e4 LT |
1386 | } |
1387 | ||
e00e56df RW |
1388 | static struct syscore_ops cpufreq_syscore_ops = { |
1389 | .suspend = cpufreq_bp_suspend, | |
1390 | .resume = cpufreq_bp_resume, | |
1da177e4 LT |
1391 | }; |
1392 | ||
9d95046e BP |
1393 | /** |
1394 | * cpufreq_get_current_driver - return current driver's name | |
1395 | * | |
1396 | * Return the name string of the currently loaded cpufreq driver | |
1397 | * or NULL, if none. | |
1398 | */ | |
1399 | const char *cpufreq_get_current_driver(void) | |
1400 | { | |
1401 | if (cpufreq_driver) | |
1402 | return cpufreq_driver->name; | |
1403 | ||
1404 | return NULL; | |
1405 | } | |
1406 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 LT |
1407 | |
1408 | /********************************************************************* | |
1409 | * NOTIFIER LISTS INTERFACE * | |
1410 | *********************************************************************/ | |
1411 | ||
1412 | /** | |
1413 | * cpufreq_register_notifier - register a driver with cpufreq | |
1414 | * @nb: notifier function to register | |
1415 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1416 | * | |
32ee8c3e | 1417 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1418 | * are notified about clock rate changes (once before and once after |
1419 | * the transition), or a list of drivers that are notified about | |
1420 | * changes in cpufreq policy. | |
1421 | * | |
1422 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1423 | * blocking_notifier_chain_register. |
1da177e4 LT |
1424 | */ |
1425 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1426 | { | |
1427 | int ret; | |
1428 | ||
d5aaffa9 DB |
1429 | if (cpufreq_disabled()) |
1430 | return -EINVAL; | |
1431 | ||
74212ca4 CEB |
1432 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1433 | ||
1da177e4 LT |
1434 | switch (list) { |
1435 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1436 | ret = srcu_notifier_chain_register( |
e041c683 | 1437 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1438 | break; |
1439 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1440 | ret = blocking_notifier_chain_register( |
1441 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1442 | break; |
1443 | default: | |
1444 | ret = -EINVAL; | |
1445 | } | |
1da177e4 LT |
1446 | |
1447 | return ret; | |
1448 | } | |
1449 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1450 | ||
1451 | ||
1452 | /** | |
1453 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1454 | * @nb: notifier block to be unregistered | |
1455 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1456 | * | |
1457 | * Remove a driver from the CPU frequency notifier list. | |
1458 | * | |
1459 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1460 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1461 | */ |
1462 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1463 | { | |
1464 | int ret; | |
1465 | ||
d5aaffa9 DB |
1466 | if (cpufreq_disabled()) |
1467 | return -EINVAL; | |
1468 | ||
1da177e4 LT |
1469 | switch (list) { |
1470 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b4dfdbb3 | 1471 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1472 | &cpufreq_transition_notifier_list, nb); |
1da177e4 LT |
1473 | break; |
1474 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1475 | ret = blocking_notifier_chain_unregister( |
1476 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1477 | break; |
1478 | default: | |
1479 | ret = -EINVAL; | |
1480 | } | |
1da177e4 LT |
1481 | |
1482 | return ret; | |
1483 | } | |
1484 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1485 | ||
1486 | ||
1487 | /********************************************************************* | |
1488 | * GOVERNORS * | |
1489 | *********************************************************************/ | |
1490 | ||
1491 | ||
1492 | int __cpufreq_driver_target(struct cpufreq_policy *policy, | |
1493 | unsigned int target_freq, | |
1494 | unsigned int relation) | |
1495 | { | |
1496 | int retval = -EINVAL; | |
7249924e | 1497 | unsigned int old_target_freq = target_freq; |
c32b6b8e | 1498 | |
a7b422cd KRW |
1499 | if (cpufreq_disabled()) |
1500 | return -ENODEV; | |
1501 | ||
7249924e VK |
1502 | /* Make sure that target_freq is within supported range */ |
1503 | if (target_freq > policy->max) | |
1504 | target_freq = policy->max; | |
1505 | if (target_freq < policy->min) | |
1506 | target_freq = policy->min; | |
1507 | ||
1508 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
1509 | policy->cpu, target_freq, relation, old_target_freq); | |
5a1c0228 VK |
1510 | |
1511 | if (target_freq == policy->cur) | |
1512 | return 0; | |
1513 | ||
1da177e4 LT |
1514 | if (cpu_online(policy->cpu) && cpufreq_driver->target) |
1515 | retval = cpufreq_driver->target(policy, target_freq, relation); | |
90d45d17 | 1516 | |
1da177e4 LT |
1517 | return retval; |
1518 | } | |
1519 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1520 | ||
1da177e4 LT |
1521 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1522 | unsigned int target_freq, | |
1523 | unsigned int relation) | |
1524 | { | |
f1829e4a | 1525 | int ret = -EINVAL; |
1da177e4 LT |
1526 | |
1527 | policy = cpufreq_cpu_get(policy->cpu); | |
1528 | if (!policy) | |
f1829e4a | 1529 | goto no_policy; |
1da177e4 | 1530 | |
5a01f2e8 | 1531 | if (unlikely(lock_policy_rwsem_write(policy->cpu))) |
f1829e4a | 1532 | goto fail; |
1da177e4 LT |
1533 | |
1534 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1535 | ||
5a01f2e8 | 1536 | unlock_policy_rwsem_write(policy->cpu); |
1da177e4 | 1537 | |
f1829e4a | 1538 | fail: |
1da177e4 | 1539 | cpufreq_cpu_put(policy); |
f1829e4a | 1540 | no_policy: |
1da177e4 LT |
1541 | return ret; |
1542 | } | |
1543 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1544 | ||
bf0b90e3 | 1545 | int __cpufreq_driver_getavg(struct cpufreq_policy *policy, unsigned int cpu) |
dfde5d62 VP |
1546 | { |
1547 | int ret = 0; | |
1548 | ||
d5aaffa9 DB |
1549 | if (cpufreq_disabled()) |
1550 | return ret; | |
1551 | ||
0676f7f2 VK |
1552 | if (!(cpu_online(cpu) && cpufreq_driver->getavg)) |
1553 | return 0; | |
1554 | ||
dfde5d62 VP |
1555 | policy = cpufreq_cpu_get(policy->cpu); |
1556 | if (!policy) | |
1557 | return -EINVAL; | |
1558 | ||
0676f7f2 | 1559 | ret = cpufreq_driver->getavg(policy, cpu); |
dfde5d62 | 1560 | |
dfde5d62 VP |
1561 | cpufreq_cpu_put(policy); |
1562 | return ret; | |
1563 | } | |
5a01f2e8 | 1564 | EXPORT_SYMBOL_GPL(__cpufreq_driver_getavg); |
dfde5d62 | 1565 | |
153d7f3f | 1566 | /* |
153d7f3f AV |
1567 | * when "event" is CPUFREQ_GOV_LIMITS |
1568 | */ | |
1da177e4 | 1569 | |
e08f5f5b GS |
1570 | static int __cpufreq_governor(struct cpufreq_policy *policy, |
1571 | unsigned int event) | |
1da177e4 | 1572 | { |
cc993cab | 1573 | int ret; |
6afde10c TR |
1574 | |
1575 | /* Only must be defined when default governor is known to have latency | |
1576 | restrictions, like e.g. conservative or ondemand. | |
1577 | That this is the case is already ensured in Kconfig | |
1578 | */ | |
1579 | #ifdef CONFIG_CPU_FREQ_GOV_PERFORMANCE | |
1580 | struct cpufreq_governor *gov = &cpufreq_gov_performance; | |
1581 | #else | |
1582 | struct cpufreq_governor *gov = NULL; | |
1583 | #endif | |
1c256245 TR |
1584 | |
1585 | if (policy->governor->max_transition_latency && | |
1586 | policy->cpuinfo.transition_latency > | |
1587 | policy->governor->max_transition_latency) { | |
6afde10c TR |
1588 | if (!gov) |
1589 | return -EINVAL; | |
1590 | else { | |
1591 | printk(KERN_WARNING "%s governor failed, too long" | |
1592 | " transition latency of HW, fallback" | |
1593 | " to %s governor\n", | |
1594 | policy->governor->name, | |
1595 | gov->name); | |
1596 | policy->governor = gov; | |
1597 | } | |
1c256245 | 1598 | } |
1da177e4 LT |
1599 | |
1600 | if (!try_module_get(policy->governor->owner)) | |
1601 | return -EINVAL; | |
1602 | ||
2d06d8c4 | 1603 | pr_debug("__cpufreq_governor for CPU %u, event %u\n", |
e08f5f5b | 1604 | policy->cpu, event); |
1da177e4 LT |
1605 | ret = policy->governor->governor(policy, event); |
1606 | ||
e08f5f5b GS |
1607 | /* we keep one module reference alive for |
1608 | each CPU governed by this CPU */ | |
1da177e4 LT |
1609 | if ((event != CPUFREQ_GOV_START) || ret) |
1610 | module_put(policy->governor->owner); | |
1611 | if ((event == CPUFREQ_GOV_STOP) && !ret) | |
1612 | module_put(policy->governor->owner); | |
1613 | ||
1614 | return ret; | |
1615 | } | |
1616 | ||
1617 | ||
1da177e4 LT |
1618 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
1619 | { | |
3bcb09a3 | 1620 | int err; |
1da177e4 LT |
1621 | |
1622 | if (!governor) | |
1623 | return -EINVAL; | |
1624 | ||
a7b422cd KRW |
1625 | if (cpufreq_disabled()) |
1626 | return -ENODEV; | |
1627 | ||
3fc54d37 | 1628 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 1629 | |
3bcb09a3 JF |
1630 | err = -EBUSY; |
1631 | if (__find_governor(governor->name) == NULL) { | |
1632 | err = 0; | |
1633 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 1634 | } |
1da177e4 | 1635 | |
32ee8c3e | 1636 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 1637 | return err; |
1da177e4 LT |
1638 | } |
1639 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
1640 | ||
1641 | ||
1642 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) | |
1643 | { | |
90e41bac PB |
1644 | #ifdef CONFIG_HOTPLUG_CPU |
1645 | int cpu; | |
1646 | #endif | |
1647 | ||
1da177e4 LT |
1648 | if (!governor) |
1649 | return; | |
1650 | ||
a7b422cd KRW |
1651 | if (cpufreq_disabled()) |
1652 | return; | |
1653 | ||
90e41bac PB |
1654 | #ifdef CONFIG_HOTPLUG_CPU |
1655 | for_each_present_cpu(cpu) { | |
1656 | if (cpu_online(cpu)) | |
1657 | continue; | |
1658 | if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name)) | |
1659 | strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0"); | |
1660 | } | |
1661 | #endif | |
1662 | ||
3fc54d37 | 1663 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 1664 | list_del(&governor->governor_list); |
3fc54d37 | 1665 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
1666 | return; |
1667 | } | |
1668 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
1669 | ||
1670 | ||
1671 | ||
1672 | /********************************************************************* | |
1673 | * POLICY INTERFACE * | |
1674 | *********************************************************************/ | |
1675 | ||
1676 | /** | |
1677 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
1678 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
1679 | * is written | |
1da177e4 LT |
1680 | * |
1681 | * Reads the current cpufreq policy. | |
1682 | */ | |
1683 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
1684 | { | |
1685 | struct cpufreq_policy *cpu_policy; | |
1686 | if (!policy) | |
1687 | return -EINVAL; | |
1688 | ||
1689 | cpu_policy = cpufreq_cpu_get(cpu); | |
1690 | if (!cpu_policy) | |
1691 | return -EINVAL; | |
1692 | ||
1da177e4 | 1693 | memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1694 | |
1695 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
1696 | return 0; |
1697 | } | |
1698 | EXPORT_SYMBOL(cpufreq_get_policy); | |
1699 | ||
1700 | ||
153d7f3f | 1701 | /* |
e08f5f5b GS |
1702 | * data : current policy. |
1703 | * policy : policy to be set. | |
153d7f3f | 1704 | */ |
e08f5f5b GS |
1705 | static int __cpufreq_set_policy(struct cpufreq_policy *data, |
1706 | struct cpufreq_policy *policy) | |
1da177e4 LT |
1707 | { |
1708 | int ret = 0; | |
1709 | ||
2d06d8c4 | 1710 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu, |
1da177e4 LT |
1711 | policy->min, policy->max); |
1712 | ||
e08f5f5b GS |
1713 | memcpy(&policy->cpuinfo, &data->cpuinfo, |
1714 | sizeof(struct cpufreq_cpuinfo)); | |
1da177e4 | 1715 | |
53391fa2 | 1716 | if (policy->min > data->max || policy->max < data->min) { |
9c9a43ed MD |
1717 | ret = -EINVAL; |
1718 | goto error_out; | |
1719 | } | |
1720 | ||
1da177e4 LT |
1721 | /* verify the cpu speed can be set within this limit */ |
1722 | ret = cpufreq_driver->verify(policy); | |
1723 | if (ret) | |
1724 | goto error_out; | |
1725 | ||
1da177e4 | 1726 | /* adjust if necessary - all reasons */ |
e041c683 AS |
1727 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1728 | CPUFREQ_ADJUST, policy); | |
1da177e4 LT |
1729 | |
1730 | /* adjust if necessary - hardware incompatibility*/ | |
e041c683 AS |
1731 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1732 | CPUFREQ_INCOMPATIBLE, policy); | |
1da177e4 LT |
1733 | |
1734 | /* verify the cpu speed can be set within this limit, | |
1735 | which might be different to the first one */ | |
1736 | ret = cpufreq_driver->verify(policy); | |
e041c683 | 1737 | if (ret) |
1da177e4 | 1738 | goto error_out; |
1da177e4 LT |
1739 | |
1740 | /* notification of the new policy */ | |
e041c683 AS |
1741 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
1742 | CPUFREQ_NOTIFY, policy); | |
1da177e4 | 1743 | |
7d5e350f DJ |
1744 | data->min = policy->min; |
1745 | data->max = policy->max; | |
1da177e4 | 1746 | |
2d06d8c4 | 1747 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e08f5f5b | 1748 | data->min, data->max); |
1da177e4 LT |
1749 | |
1750 | if (cpufreq_driver->setpolicy) { | |
1751 | data->policy = policy->policy; | |
2d06d8c4 | 1752 | pr_debug("setting range\n"); |
1da177e4 LT |
1753 | ret = cpufreq_driver->setpolicy(policy); |
1754 | } else { | |
1755 | if (policy->governor != data->governor) { | |
1756 | /* save old, working values */ | |
1757 | struct cpufreq_governor *old_gov = data->governor; | |
1758 | ||
2d06d8c4 | 1759 | pr_debug("governor switch\n"); |
1da177e4 LT |
1760 | |
1761 | /* end old governor */ | |
ffe6275f | 1762 | if (data->governor) |
1da177e4 LT |
1763 | __cpufreq_governor(data, CPUFREQ_GOV_STOP); |
1764 | ||
1765 | /* start new governor */ | |
1766 | data->governor = policy->governor; | |
1767 | if (__cpufreq_governor(data, CPUFREQ_GOV_START)) { | |
1768 | /* new governor failed, so re-start old one */ | |
2d06d8c4 | 1769 | pr_debug("starting governor %s failed\n", |
e08f5f5b | 1770 | data->governor->name); |
1da177e4 LT |
1771 | if (old_gov) { |
1772 | data->governor = old_gov; | |
e08f5f5b GS |
1773 | __cpufreq_governor(data, |
1774 | CPUFREQ_GOV_START); | |
1da177e4 LT |
1775 | } |
1776 | ret = -EINVAL; | |
1777 | goto error_out; | |
1778 | } | |
1779 | /* might be a policy change, too, so fall through */ | |
1780 | } | |
2d06d8c4 | 1781 | pr_debug("governor: change or update limits\n"); |
1da177e4 LT |
1782 | __cpufreq_governor(data, CPUFREQ_GOV_LIMITS); |
1783 | } | |
1784 | ||
7d5e350f | 1785 | error_out: |
1da177e4 LT |
1786 | return ret; |
1787 | } | |
1788 | ||
1da177e4 LT |
1789 | /** |
1790 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
1791 | * @cpu: CPU which shall be re-evaluated | |
1792 | * | |
25985edc | 1793 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
1794 | * at different times. |
1795 | */ | |
1796 | int cpufreq_update_policy(unsigned int cpu) | |
1797 | { | |
1798 | struct cpufreq_policy *data = cpufreq_cpu_get(cpu); | |
1799 | struct cpufreq_policy policy; | |
f1829e4a | 1800 | int ret; |
1da177e4 | 1801 | |
f1829e4a JL |
1802 | if (!data) { |
1803 | ret = -ENODEV; | |
1804 | goto no_policy; | |
1805 | } | |
1da177e4 | 1806 | |
f1829e4a JL |
1807 | if (unlikely(lock_policy_rwsem_write(cpu))) { |
1808 | ret = -EINVAL; | |
1809 | goto fail; | |
1810 | } | |
1da177e4 | 1811 | |
2d06d8c4 | 1812 | pr_debug("updating policy for CPU %u\n", cpu); |
7d5e350f | 1813 | memcpy(&policy, data, sizeof(struct cpufreq_policy)); |
1da177e4 LT |
1814 | policy.min = data->user_policy.min; |
1815 | policy.max = data->user_policy.max; | |
1816 | policy.policy = data->user_policy.policy; | |
1817 | policy.governor = data->user_policy.governor; | |
1818 | ||
0961dd0d TR |
1819 | /* BIOS might change freq behind our back |
1820 | -> ask driver for current freq and notify governors about a change */ | |
1821 | if (cpufreq_driver->get) { | |
1822 | policy.cur = cpufreq_driver->get(cpu); | |
a85f7bd3 | 1823 | if (!data->cur) { |
2d06d8c4 | 1824 | pr_debug("Driver did not initialize current freq"); |
a85f7bd3 TR |
1825 | data->cur = policy.cur; |
1826 | } else { | |
1827 | if (data->cur != policy.cur) | |
e08f5f5b GS |
1828 | cpufreq_out_of_sync(cpu, data->cur, |
1829 | policy.cur); | |
a85f7bd3 | 1830 | } |
0961dd0d TR |
1831 | } |
1832 | ||
1da177e4 LT |
1833 | ret = __cpufreq_set_policy(data, &policy); |
1834 | ||
5a01f2e8 VP |
1835 | unlock_policy_rwsem_write(cpu); |
1836 | ||
f1829e4a | 1837 | fail: |
1da177e4 | 1838 | cpufreq_cpu_put(data); |
f1829e4a | 1839 | no_policy: |
1da177e4 LT |
1840 | return ret; |
1841 | } | |
1842 | EXPORT_SYMBOL(cpufreq_update_policy); | |
1843 | ||
dd184a01 | 1844 | static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, |
c32b6b8e AR |
1845 | unsigned long action, void *hcpu) |
1846 | { | |
1847 | unsigned int cpu = (unsigned long)hcpu; | |
8a25a2fd | 1848 | struct device *dev; |
c32b6b8e | 1849 | |
8a25a2fd KS |
1850 | dev = get_cpu_device(cpu); |
1851 | if (dev) { | |
c32b6b8e AR |
1852 | switch (action) { |
1853 | case CPU_ONLINE: | |
8bb78442 | 1854 | case CPU_ONLINE_FROZEN: |
8a25a2fd | 1855 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1856 | break; |
1857 | case CPU_DOWN_PREPARE: | |
8bb78442 | 1858 | case CPU_DOWN_PREPARE_FROZEN: |
5a01f2e8 VP |
1859 | if (unlikely(lock_policy_rwsem_write(cpu))) |
1860 | BUG(); | |
1861 | ||
8a25a2fd | 1862 | __cpufreq_remove_dev(dev, NULL); |
c32b6b8e | 1863 | break; |
5a01f2e8 | 1864 | case CPU_DOWN_FAILED: |
8bb78442 | 1865 | case CPU_DOWN_FAILED_FROZEN: |
8a25a2fd | 1866 | cpufreq_add_dev(dev, NULL); |
c32b6b8e AR |
1867 | break; |
1868 | } | |
1869 | } | |
1870 | return NOTIFY_OK; | |
1871 | } | |
1872 | ||
9c36f746 | 1873 | static struct notifier_block __refdata cpufreq_cpu_notifier = { |
c32b6b8e AR |
1874 | .notifier_call = cpufreq_cpu_callback, |
1875 | }; | |
1da177e4 LT |
1876 | |
1877 | /********************************************************************* | |
1878 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
1879 | *********************************************************************/ | |
1880 | ||
1881 | /** | |
1882 | * cpufreq_register_driver - register a CPU Frequency driver | |
1883 | * @driver_data: A struct cpufreq_driver containing the values# | |
1884 | * submitted by the CPU Frequency driver. | |
1885 | * | |
32ee8c3e | 1886 | * Registers a CPU Frequency driver to this core code. This code |
1da177e4 | 1887 | * returns zero on success, -EBUSY when another driver got here first |
32ee8c3e | 1888 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
1889 | * |
1890 | */ | |
221dee28 | 1891 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
1892 | { |
1893 | unsigned long flags; | |
1894 | int ret; | |
1895 | ||
a7b422cd KRW |
1896 | if (cpufreq_disabled()) |
1897 | return -ENODEV; | |
1898 | ||
1da177e4 LT |
1899 | if (!driver_data || !driver_data->verify || !driver_data->init || |
1900 | ((!driver_data->setpolicy) && (!driver_data->target))) | |
1901 | return -EINVAL; | |
1902 | ||
2d06d8c4 | 1903 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 LT |
1904 | |
1905 | if (driver_data->setpolicy) | |
1906 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
1907 | ||
1908 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1909 | if (cpufreq_driver) { | |
1910 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1911 | return -EBUSY; | |
1912 | } | |
1913 | cpufreq_driver = driver_data; | |
1914 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1915 | ||
8a25a2fd | 1916 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab JS |
1917 | if (ret) |
1918 | goto err_null_driver; | |
1da177e4 | 1919 | |
8f5bc2ab | 1920 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY)) { |
1da177e4 LT |
1921 | int i; |
1922 | ret = -ENODEV; | |
1923 | ||
1924 | /* check for at least one working CPU */ | |
7a6aedfa MT |
1925 | for (i = 0; i < nr_cpu_ids; i++) |
1926 | if (cpu_possible(i) && per_cpu(cpufreq_cpu_data, i)) { | |
1da177e4 | 1927 | ret = 0; |
7a6aedfa MT |
1928 | break; |
1929 | } | |
1da177e4 LT |
1930 | |
1931 | /* if all ->init() calls failed, unregister */ | |
1932 | if (ret) { | |
2d06d8c4 | 1933 | pr_debug("no CPU initialized for driver %s\n", |
e08f5f5b | 1934 | driver_data->name); |
8a25a2fd | 1935 | goto err_if_unreg; |
1da177e4 LT |
1936 | } |
1937 | } | |
1938 | ||
8f5bc2ab | 1939 | register_hotcpu_notifier(&cpufreq_cpu_notifier); |
2d06d8c4 | 1940 | pr_debug("driver %s up and running\n", driver_data->name); |
1da177e4 | 1941 | |
8f5bc2ab | 1942 | return 0; |
8a25a2fd KS |
1943 | err_if_unreg: |
1944 | subsys_interface_unregister(&cpufreq_interface); | |
8f5bc2ab JS |
1945 | err_null_driver: |
1946 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1947 | cpufreq_driver = NULL; | |
1948 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
4d34a67d | 1949 | return ret; |
1da177e4 LT |
1950 | } |
1951 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
1952 | ||
1953 | ||
1954 | /** | |
1955 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
1956 | * | |
32ee8c3e | 1957 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
1958 | * the right to do so, i.e. if you have succeeded in initialising before! |
1959 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
1960 | * currently not initialised. | |
1961 | */ | |
221dee28 | 1962 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
1963 | { |
1964 | unsigned long flags; | |
1965 | ||
2d06d8c4 | 1966 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 1967 | return -EINVAL; |
1da177e4 | 1968 | |
2d06d8c4 | 1969 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 1970 | |
8a25a2fd | 1971 | subsys_interface_unregister(&cpufreq_interface); |
65edc68c | 1972 | unregister_hotcpu_notifier(&cpufreq_cpu_notifier); |
1da177e4 LT |
1973 | |
1974 | spin_lock_irqsave(&cpufreq_driver_lock, flags); | |
1975 | cpufreq_driver = NULL; | |
1976 | spin_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1977 | ||
1978 | return 0; | |
1979 | } | |
1980 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 VP |
1981 | |
1982 | static int __init cpufreq_core_init(void) | |
1983 | { | |
1984 | int cpu; | |
1985 | ||
a7b422cd KRW |
1986 | if (cpufreq_disabled()) |
1987 | return -ENODEV; | |
1988 | ||
5a01f2e8 | 1989 | for_each_possible_cpu(cpu) { |
f1625066 | 1990 | per_cpu(cpufreq_policy_cpu, cpu) = -1; |
5a01f2e8 VP |
1991 | init_rwsem(&per_cpu(cpu_policy_rwsem, cpu)); |
1992 | } | |
8aa84ad8 | 1993 | |
8a25a2fd | 1994 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 | 1995 | BUG_ON(!cpufreq_global_kobject); |
e00e56df | 1996 | register_syscore_ops(&cpufreq_syscore_ops); |
8aa84ad8 | 1997 | |
5a01f2e8 VP |
1998 | return 0; |
1999 | } | |
5a01f2e8 | 2000 | core_initcall(cpufreq_core_init); |